Metal strut



E. B. CARNS Aug. 20, 1929.

METAL STRUT Original Filed March 5, 1927 Patented Aug. 20, 1929,

PATEN EDHUN'D BURKE CABINS, 01' NEW YORK, N. Y.

lunar. s'rnu'r.

Application fled larch 5, 1887, Serial No. 178,087. Renewed January 14, 1889.

My invention relates to improvements in is to produce a metal strut having a maximum of strength and a minimum of weight. The invention is intended primarily for use in aeroplanes, although it can be used for other purposes, but it is especially designed for use in fuselage and wing structures of aeroplanes to brace various parts and to this end it is desirable to have a strut which is very strongin proportion to its weight. The invention, therefore, is to be a structure that can be built commercially to a figured stress requirement and lose none of its structural value when joined to other members.

My invention also embraces the method of makin a strut/of a kind hereinafter describe My invention is also intended to produce a strut which can be conveniently and commercially made from metal Ts and comprises the shaping and unitin of these Ts to form a strut having the desired char acteristics. This will be better understood from the description which follows:

Reference is to be had to the accompanying drawings orming a part of this speciflcation in w ich similar reference characters ind views.

Fig. 1 is a perspective view of a conventional T used in the manufacture of my improved strut.

Fig. 2 is a perspective view showing the T as shaped for use and for combining with another similar T.

Fig. 3 is a side elevation of the complete strut.

Fig. 4 is a broken end perspective showing how the strut can be made to have a mortise end.

Fig. 5 is an end perspective showin h w the strut can be made with a tenon en and Fig. 6 is a broken end perspective showing another form of the strut end.

In carrying out my invention I employ metal Ts of conventional shape comprising, as shown in Fig. 1, the flange 10 and web 11. This T is bent or curved so that the flange 10 will be bent and crowning as shown at Fig. 2 and the web 11 when the T is bent will be bent down to the line 12 in Fig. 2. The web is afterwards cut off straight as shown at 13, thus makin the web '11 of a reduced height at the en portions of the T and, if desired, the extreme end portions .of

icate porresponding parts in all the.

the web 11 can be cut away as shown at 14,

r OFFICE.

so that a mortise will be formed in the complete structure, as hereinafter described. The extreme end portions 15 of the flange 10 are left of the normal width of the flange and are unbent so that when two Ts are brought together, as presently described, the end parts 15 will be generally parallel, as shown in Fi 3. These end portions can be perforated i desired as shown at 18 to facilitate bolt attachments, and the web 11 is also perforated at the necessary ints as shown at 17. When two Ts have n thus formed, they are placed together with the webs overlapping and rivets 17' or equivalent fastenings mserted in the register' holes 17 of the two webs 11, and thus when the two parts of the strut, that is, the two Ts, are united in this wa a strong structure is formed, which will thickest in the middle and will-ta will be noted that t e web of one T member will near the end portions bear against the flange of the other member thus strengthening the same and taking the shearin strain off the fastening elements 17. Be ore the parts are united, as above stated, the flanges 10 can be reduced between their middle and end portions, as shown at 16 and as the flanges and webs are both reduced, it will.

be seen that the structure as a whole can be figured so that the metal will be. in a .way to produce the greatest strength in proportion to the weight and no surplus metal need be used.

In the formation of the T in the manner described, if the parts 14 are cut away, as indicated in Figs. 1 and 2, mortises 19 will be left between the end portions 15 of the two T flanges, which in some cases is desirable, but on the other hand if a tenon is to be formed on either or both ends of the strut the flanges can be cut away at the end parts, as shown in Fig. 5 leaving a protrudr towards the ends. It

ingtenon 20. If desire the web members located at desired points so as to make the strut, as a whole, a commercial economical structure. I have shown a design of strut which is capable of use in many arts of 5 aeroplane construction, a use to w ich the strut is especially designed, but obviously the structure is not limited to any particular use.

I claim:

1. An improved strut element comprlslng a metal T. bent to a curve with its web straight on its outer edge, with its flange reduced in width between the middle and end rtions and with the end portions of the ange projecting beyond the ends of the web. 2. An improved strut element comprisin a metal T bent to a curve with its we straight on its outer edge, with its flange gradually reduced from the middle towards the end parts, and with the end portions of the flange perforated and projecting beyond the end portions of the web. 7

3. An improved strut com rising two 0 positely curved metal Ts wit separate we 3 reduced in height towards the ends disposed to lie one against the other with the outer edge of one web-bearing for at leasta part of its length against the flange of the opposed member, said'webs being fastened to- 1 a0 ether and the flanges being gradually reuced from the middle towards the ends of the strut.

4. An improved metal strut comprising two oppositely curved metal Ts with separate webs reduced in height towards the ends disposed to lie one against the other with the outer edge of one web bearin for at least a part of its length against the ange of the opposed member, said webs bein ing ends of the flanges relatively wide and parallel with each other.

6. An improved strut element comprising a metal T bent to a curve in the plane of its web, said T having the outer edge of its web substantially straight and with its flange reduced from the middle towards the end parts.

7.-'An im roved strut comprising two reduced from'the mid le portlon tometal Ts with the web of each bearing in part against the flange of the other, said webs being fastened together, said Ts having flanges curved in the plane of said webs and said webs being reduced in height towards the ends.

In testimony whereof, I have signed my name to this specification this 4th day of March, 1927.

EDMUND BURKE ca ms. 

